Defects in steel pipes utilized in pipelines can result in fatigue and failure of the pipe when the pipe undergoes stress such as can occur during the transportation of hydrocarbon compounds, such as oil and natural gas. For a steel pipe with corrosion, dents, gouges and/or cracks, the primary stress in the pipe is exerted in the hoop direction. Therefore, common composite reinforcement or repair systems have been directed to reducing these hoop stresses on the pipe thus preventing fatigue and failure. However, in a wrinkle bend, the most common failure occurs due to high amounts of strain in the axial direction of the pipe. Traditional composite reinforcement systems have not been able to adequately reinforce the pipes at wrinkle bends when installed using traditional application techniques.
Wrinkle bends are introduced in a pipe during construction; typically, they are introduced during alignment of the pipe by bending. Bending practices used during pipeline construction often resulted in circumferential pipe deformation or wrinkles on the inside bend radius of the pipe. Vintage wrinkle bends are often of the wave shape with outward deformations. Additionally, “mild ripples” are those developed using modern day field-bending techniques where such ripples bear a length to height ratio on the order of 12. Whereas the wrinkle bends found typically on vintage built pipelines are sharper than these ripples with length to height ratio on the order of 4.